The impact of cumulus cell viability and pre-culture with the healthy cell mass on brilliant cresyl blue (BCB) staining assessment and meiotic competence of suboptimal porcine oocytes

Wanniarachchige Tharindu Lakshitha Fonseka ¹, Son Quang Do ¹, Phong Ngoc Van ¹

⁰Department of Animal Science, Graduate School of Environmental and Life Science, Okayama University, Okayama, Japan.

Theriogenology +

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June 20, 2024

View abstract on PubMed

Summary

Suboptimal porcine oocytes with low glucose-6-phosphate dehydrogenase activity (BCB-negative) can be improved. Pre-culturing these oocytes with healthy cumulus cell masses enhances their meiotic competence.

Area Of Science

Reproductive Biology
Animal Science
Cell Biology

Background

Suboptimal porcine oocytes, identified by Brilliant Cresyl Blue (BCB) staining, present challenges in achieving full meiotic competence.
The health and composition of surrounding cumulus cell masses (CCMs) may influence oocyte quality and developmental potential.
Understanding the characteristics of BCB-negative (BCB-) oocytes is crucial for improving assisted reproductive technologies in swine.

Purpose Of The Study

To characterize suboptimal porcine oocytes, specifically assessing glucose-6-phosphate dehydrogenase activity via BCB staining.
To investigate methods for enhancing the meiotic competence of these suboptimal oocytes.
To explore the role of cumulus cell masses (CCMs) in regulating oocyte quality and maturation.

Main Methods

Porcine oocyte-cumulus complexes (OCCs) from small (SF) and medium follicles (MF) were assessed using BCB staining.
Oocytes were exposed to an apoptosis inducer to evaluate the impact on BCB status and meiotic progression.
Pre-culture of BCB-negative oocytes with cumulus cell masses from healthy oocytes was performed before in vitro maturation (IVM).

Main Results

A higher percentage of BCB-negative oocytes originated from small follicles (SF).
BCB-negative oocytes were associated with a greater degree of cumulus cell death.
Pre-culturing suboptimal BCB-negative oocytes with healthy cumulus cell masses significantly improved their meiotic competence, particularly those from SF.

Conclusions

The BCB status of porcine oocytes is significantly influenced by the health and composition of the surrounding cumulus cells.
Pre-culture with healthy cumulus cell masses is an effective strategy to improve the meiotic competence of suboptimal BCB-negative porcine oocytes.
This approach holds promise for enhancing the efficiency of swine oocyte maturation and breeding programs.

Keywords:

Brilliant cresyl blue Cumulus cells Meiotic competence Oocytes